Control apparatus for pumps



Aug. 15, 1933. w. FLETCHER 1,922,427

CONTROL APPARATUS FOR PUMPS Filed Oct. 19, 1951 FIG. 2

FIG.1

[INIT HAIOLD n'. FLETCHER l NVENTOR y WHW ATTDRN EY VPatented Aug. 15,V 1933 i 4"UNITED STATES PATENT OFFICE CONTROL APPARATUS FOR PUMPS Harold Wheelock Fletcher, Houston, Tex., as-

signor to Hughes Tool Company, Houston, Tex., a Corporation of Texas l Application October 19, 19341. Serial No. 569,674

' s claims. (el. l10a-52) My invention relates to pumps of the pneuinvention. Fig. 2 is a vertical section through matic' swab type in which a freely movable swab the lower end of the eduction tube. plunger is employed to lift a load of liquid to the Fig.3 is a sectional detail of the back pressure surface through pneumatic'pressure. valve employed.

In such apparatus the plunger is raised with The pneumatic swab device to which mylinvent@ its load of liquid through gas or air pressurebetion is applied is one now old in the art. It in low theplunger. Where gas is 4present inthe cludes a well casing 1 having a casing head 2 producing formation, the gas is allowed to accuwith alateral pipe 3 connected therewith. This mulate below the plunger and its load until it pipe is ordinarily employed as an inlet for presl exerts sufficient pressure to lift it to the surface. Sure uid when necessary. It vhas'a hand epele- '40 this character in addition to the usual choke,

When the load is discharged and the plunger is ed Valve 5 therein and a relief Valve 4 Of any Dred forced `past the outlet with sufficient force to ferred form to relieve the gas pressure in the well compress the air and liquid in the closed upper when` it exceeds the desired maximum amount, end of the eduction tube, the 'trapped uid above The upper end 0f the Casing heed has e bonnet the plunger will thus :force the vplunger valve 6 threaded at 'GS upper end et 7 te engage the YU open, allowing the plunger to fall. where cem- `upper Seetion 8 0f the edueton tube and form pressed air is used the operation is practically a Seal therewith. A 1 Y Y the same, On the inner face of the casing head is a shoul- Due to the fact that the gas Whichlifts the del 9 t0 SUDPOI'Y the bushing 10 llDOIl the edu@- plunger musi', escape fron'lY behind the plunger OII tube 11. Said bushing iS Connected With the '[5 after the load is discharged, the plunger will vtube vand sustains the weight of the tube which drop back before theV gas under its accumulated extends downwardly into the well. Said tube has .pressure has had time to escape. If this gas is e strainer 12 connected therewith by means of a allowed to escape quickly itV will interfere with peeel eeupling'lS having a stop Spider 14 thelethe dropping of the plunger and will blow it 1n- 53 back up into the upper end of the tube. A choke The PIU-nger 15. in the tube s'of the Pjefe'red is therefore employed inthe discharge line from 'f01`In W1t-h a @We 16' the'em Supported 1n Open the pump to 510W down the rate of dl'scharge so position upon the head 17 but adapted to close that the plunger can fall through the escaping upwardly mto the se@ 18 when the Stem 19 on n" gas and not be materiauy impeded the valve contacts with the stop 14. es Heretofore a choke valve has been employed The eductlon tube has a' losed upperlend 8 in the discharge line but such a valve maintains Whlch has a' buffer 20 therem. for the punger' a xed Opening which has to accommodate the Lateral slots 21 1n the tube provide outlets for the passage of both liquid and gas. When the choke mud to the Outlet pme 22 leadmg to Storage' U0 is set for the liquid, it does not suiciently choke tolllsdghe meg 's gg a'llolzi down the flow of gas.

device which may be connected in the line by It 1S, an Ome. of the-lnvent1on to provlde a closing a gate valve 24. 'Ihis choke, shown at 25, valve 1n the discharge l1ne of an apparatus of is Coupled ln a bypass 26 connected to the dls charge line at both sides of the gate valve 24. 95 which valve will be responsive to the pressure of The choke has been illustrated in the C0pend different fluids to slow down the flow of gaseous lng appllcatlon of Norman H. Rieker, Serial N0 fluid, but will not greatly impede the passage 0f 560,271,1i1ed August 31, 1931. It includes a housllquid. ing with a seat to receive a needle shaped valve I form in combination with the choke valve Operated by the stem 27 to provide an Opening 10o usually employed, an additional valve of the back throughthe bypass of the desired capacity. pleSSllI'e type, WhCh tOgethel With the Choke I place a back pressure valve, the housing of will control the discharge of liquid and gas to which is shown at, 28, in the bypass on the upthe desired rate. stream side of the choke. In Fig. 3 it will be seen I eJSO Provide means t0 prevent undue accumuthat this back pressure valve includes a valve l lation of gas in the well casing, so as to regulate member 29 fitting within the seat 30 in a passage the pressure of gas in the well. through the housing 28 and adapted to be held In the drawing herewith, Fig. 1 is a broken in its seat by a coiled spring 31 which is a comside view, largely in central vertical section, paratively strong spring opposing any but a small showing a well head equipped according to my opening of the valve and adjustable as to ten ll-O rate of low to a predetermined amount by reduc- Y ing the size of the passage to a fixed orice thus allowing a small pressure dropV across the valve 29.

The gas or air will also unseat the valve 29, but as it is more fluid and will flow faster, and the pressure thereon being the same, the valve will not unseat more than is necessary to allow the desirecl rate of flow of the gas. This is dueto the fact that the choke will not greatly impede the iiow of gas or air because of the greater fluidity of the air and there will be a marked pressure drop across the valve. As the spring is strong, it will resist opening'of the valve beyond a slight amount such as is desired. Thus the iiow of Agas is choked down by the back'y .pressure valve to the desired rate, and the liquid is choked down lby thechokevalve 25 tothe desired rate of iiow, and I am thusV enabled lto yslowthe discharge of both liquid and gas down so that it will allow the plunger to fall in the tube after'` the load is relieved without ydanger of the plunger being blown Aup to thetop repeatedly by the rise of the escaping gas, after the load is discharged. The tension of the spring 3l, being adjustable, it is possible to easily regulate the discharge flow of the gas to suit the conditions of gas pressure experienced in the well. Y

Thus, in use of the pneumatic swab device, I am enabled to prevent undue pressure in the well through my relief valve. Further, in the operation of the plunger, the load of liquid above the plunger wil be'discharged slowly at the desired rate by the adjustment ofthe choke valve 25 and therate of escape of the lgas, will be regulated by the back pressure valve through theadjustment of the tension on the valve spring 31.- The'rate of operation can be controlledand the plunger is assured of falling directly to the bottom after Y Y the Valve 16 in theplunger has been forced open by the pressure of fluid trapped in the closed upper end 8 of the tube.

What I claim as new is: 1. A pneumatic swab device including a casing, a casing head thereon, an eduction tube in said casing adapted to discharge liquid into said casing head, an outlet line from said casing head, a choke valve in said line and a back pressure valve between said choke Valve and said casing head.

2. A pneumatic swab device including a casing, a casing head thereon, an eduction tube'in said casing adapted to discharge liquid into said casing head, an outlet line from said casing head, a choke valve in said line and a back pressure valve between said choke valve and said casing head, and means to adjust the pressure on said back `pressure'valve tending to hold it seated.

3, In a pneumatic swab device, a well casing, a casing head thereon, an eduction tube in said casing and extending above said casing head, means to seal said casing head about said tube at the upper end thereof, said tube being formed to discharge into said casing head, a plunger in said tube, an outlet pipe from said casing head, a bypass on said pipe, a choke valve in said bypass and a back pressure valve in said bypass adjustable to control the iiow of gas therethrough. 4; The combination `in the discharge line of a vpneumatic swab device of a choke device providing airlxed orifice for` the control of the flow of liquid,and Va back Ypressurevalve adjustable to control the flow of gaseous fluid therethrough.

5; In apneumatic swab device a well casing, a casing head, av bonnet closing the upper end of said casi-ng head, an eduction tube fitti-ng through said bonnet -into said casing, means to relieve excessive pressure in said casing, and means on said .casingl head to regulate the ow of liquid and separate means to regulate the flow of gaseous fluid.

6. In a pneumatic swab device a Well casing, a casing head, a bonnet closing the upper end of said casing head, an eduction tube fitting through said bonnet into said casing, and automatically operating means to relieve excessive pressure in said casing.

HAROLD WHEELOCK FLETCHER. 

